Shipping containers

The London Gateway is a newly opened container port on the River Thames, close to London and the transport infrastructure of south-east England. It has been designed to handle some of the largest container ships in the world today. Our Saturday newspaper had a long article about this site. Having read the article, there was one fact that could be used by Google as the basis of an interview question: "How many movements of shipping containers happen each year in the world?" Tina and I thought about how we would approach the guesstimation of the answer. We know that many millions of cars are moved each year in shipping containers, so transport of vehicles accounts for somewhere between 5 and 50 million container movements, and vehicles must be one of the larger uses of containers ... so we reckoned that we would estimate between 100 million and 1000 million container movements. The answer in the article is 500 million.

At one O.R. conference that I attended, there was a speaker who described how the growth of container shipments and the ports that handle them had revolutionised international trade. But, he argued, the revolution depended on the simultaneous growth of computer power, and the development of algorithms for managing those containers and their contents. Which is why the lecture was given to O.R. people. Efficient container management requires forecasting of demand for goods, months ahead. It requires supply chain management. It requires fleet management for the ships and dockside equipment. It requires routing algorithms for loading and unloading the ships. It requires personnel forecasting and management for the fleets and ports. Many of the containers are used in "Just in Time" supply or manufacture. The list of areas of O.R. expertise goes on and on. To make the article appeal to a non-specialist readership, the news article was headed "It's like a giant Tetris" linking the colourful Tetris blocks to the colourful 40ft containers. Maybe experience with devising rules for beating the computer at Tetris can be used to suggest heuristics for moving these larger coloured blocks?

Sadly, despite the many contributions of O.R. to international container shipping, the term did not appear. We really are the "Hidden science"!

Thank you, Paul. I had not come across the parallel between Towers of Hanoi and container stacking. An interesting link and testimony to the use of O.R. in this type of problem. I suspect that there are inbuilt heuristics despite the use of Constraint Programming, because there will seldom be one and only one place for a newly arrived container.